Conventionally, there is apprehension or concern about whether radio waves from cellular phones have bad influence. For example, there is a person to have a concern about a possibility that a medical instrument, such as a cardiac pacemaker may malfunction because of radio waves from cellular phones. To address such a concern, a device dedicated for forcibly restricting radio transmission from a cellular phone is provided. If a certain cellular phone approaches the dedicated device, the radio transmission from the certain cellular phone can be restricted. Further, a zone for restricting radio transmission is previously defined so as to restrict the radio transmission from a cellular phone. When a cellular phone itself determines to be located within the zone for restricting radio transmission, the cellular phone restricts or stops own radio transmission in the zone. (for example, refer to Patent Document 1).    Patent Document 1: JP 2004-15567 A
The above technology or method described in Patent document 1 is practical or effective when the zone for restring radio transmission is previously specified. In other words, it is impossible to switch whether or not to restrict radio transmission from a cellular phone regardless of the zone.